From 9cd67421977a701272820987ff9e6f197b1b97b7 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Thu, 25 Dec 2008 13:39:06 +0100 Subject: [S390] cio: Fix reference counting for online/offline. The current code attempts to get an extra reference count for online devices by doing a get_device() in ccw_device_online() and a put_device() in ccw_device_done(). However, this - incorrectly obtains an extra reference for disconnected devices becoming available again (since they are already online) - needs special checks for css_init_done in order to handle the console device - is not obvious and - may incorretly drop a reference count in ccw_device_done() if that function is called after path verification for a device that just became not operational. So let's just get the reference in ccw_device_set_online() and drop it in ccw_device_set_offline(). (Unfortunately, we still need the special case in io_subchannel_probe().) Signed-off-by: Cornelia Huck Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_fsm.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers/s390/cio/device_fsm.c') diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index 10bc03940fb3..01330cf5ae5e 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -399,9 +399,6 @@ ccw_device_done(struct ccw_device *cdev, int state) ccw_device_oper_notify(cdev); } wake_up(&cdev->private->wait_q); - - if (css_init_done && state != DEV_STATE_ONLINE) - put_device (&cdev->dev); } static int cmp_pgid(struct pgid *p1, struct pgid *p2) @@ -611,8 +608,6 @@ ccw_device_online(struct ccw_device *cdev) (cdev->private->state != DEV_STATE_BOXED)) return -EINVAL; sch = to_subchannel(cdev->dev.parent); - if (css_init_done && !get_device(&cdev->dev)) - return -ENODEV; ret = cio_enable_subchannel(sch, (u32)(addr_t)sch); if (ret != 0) { /* Couldn't enable the subchannel for i/o. Sick device. */ -- cgit v1.2.3 From cdb912a40df8b8507ab60b3d52f9980c0ba1f44d Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Dec 2008 13:39:12 +0100 Subject: [S390] cio: introduce cio_update_schib There is the chance that we get condition code 0 for a stsch but the resulting schib is not vaild. In the current code there are 2 cases: * we do a check for validity of the schib after stsch, but at this time we have already stored the invaild schib in the subchannel structure. This may lead to problems. * we don't do a check for validity, which is not that good either. The patch addresses both issues by introducing the stsch wrapper cio_update_schib which performs stsch on a local schib. This schib is only written back to the subchannel if it's valid. side note: For some functions (chp_events) the return codes are different now (-ENXIO vs -ENODEV) but this shouldn't do harm since the caller doesn't check for _specific_ errors. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_fsm.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'drivers/s390/cio/device_fsm.c') diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index 01330cf5ae5e..e1a3786779ba 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -140,8 +140,7 @@ ccw_device_cancel_halt_clear(struct ccw_device *cdev) int ret; sch = to_subchannel(cdev->dev.parent); - ret = stsch(sch->schid, &sch->schib); - if (ret || !sch->schib.pmcw.dnv) + if (cio_update_schib(sch)) return -ENODEV; if (!sch->schib.pmcw.ena) /* Not operational -> done. */ @@ -245,11 +244,13 @@ ccw_device_recog_done(struct ccw_device *cdev, int state) * through ssch() and the path information is up to date. */ old_lpm = sch->lpm; - stsch(sch->schid, &sch->schib); - sch->lpm = sch->schib.pmcw.pam & sch->opm; + /* Check since device may again have become not operational. */ - if (!sch->schib.pmcw.dnv) + if (cio_update_schib(sch)) state = DEV_STATE_NOT_OPER; + else + sch->lpm = sch->schib.pmcw.pam & sch->opm; + if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID) /* Force reprobe on all chpids. */ old_lpm = 0; @@ -549,7 +550,11 @@ ccw_device_verify_done(struct ccw_device *cdev, int err) sch = to_subchannel(cdev->dev.parent); /* Update schib - pom may have changed. */ - stsch(sch->schid, &sch->schib); + if (cio_update_schib(sch)) { + cdev->private->flags.donotify = 0; + ccw_device_done(cdev, DEV_STATE_NOT_OPER); + return; + } /* Update lpm with verified path mask. */ sch->lpm = sch->vpm; /* Repeat path verification? */ @@ -667,7 +672,7 @@ ccw_device_offline(struct ccw_device *cdev) return 0; } sch = to_subchannel(cdev->dev.parent); - if (stsch(sch->schid, &sch->schib) || !sch->schib.pmcw.dnv) + if (cio_update_schib(sch)) return -ENODEV; if (scsw_actl(&sch->schib.scsw) != 0) return -EBUSY; @@ -745,7 +750,10 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event) * Since we might not just be coming from an interrupt from the * subchannel we have to update the schib. */ - stsch(sch->schid, &sch->schib); + if (cio_update_schib(sch)) { + ccw_device_verify_done(cdev, -ENODEV); + return; + } if (scsw_actl(&sch->schib.scsw) != 0 || (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) || @@ -1011,9 +1019,7 @@ void ccw_device_trigger_reprobe(struct ccw_device *cdev) sch = to_subchannel(cdev->dev.parent); /* Update some values. */ - if (stsch(sch->schid, &sch->schib)) - return; - if (!sch->schib.pmcw.dnv) + if (cio_update_schib(sch)) return; /* * The pim, pam, pom values may not be accurate, but they are the best -- cgit v1.2.3 From 13952ec12dfeea793ff83c2a96139ed57eb0b897 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Dec 2008 13:39:13 +0100 Subject: [S390] cio: introduce cio_commit_config To change the configuration of a subchannel we alter the modifiable bits of the subchannel's schib field and issue a modify subchannel. There can be the case that not all changes were applied -or worse- quietly overwritten by the hardware. With the next store subchannel we obtain the current state of the hardware but lose our target configuration. With this patch we introduce a subchannel_config structure which contains the target subchannel configuration. Additionally the msch wrapper cio_modify is replaced with cio_commit_config which copies the desired changes to a temporary schib. msch is then called with the temporary schib. This schib is only written back to the subchannel if all changes were applied. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_fsm.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/s390/cio/device_fsm.c') diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index e1a3786779ba..9e249675c98d 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -1026,11 +1026,12 @@ void ccw_device_trigger_reprobe(struct ccw_device *cdev) * we have before performing device selection :/ */ sch->lpm = sch->schib.pmcw.pam & sch->opm; - /* Re-set some bits in the pmcw that were lost. */ - sch->schib.pmcw.csense = 1; - sch->schib.pmcw.ena = 0; - if ((sch->lpm & (sch->lpm - 1)) != 0) - sch->schib.pmcw.mp = 1; + /* + * Use the initial configuration since we can't be shure that the old + * paths are valid. + */ + io_subchannel_init_config(sch); + /* We should also udate ssd info, but this has to wait. */ /* Check if this is another device which appeared on the same sch. */ if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) { -- cgit v1.2.3 From f444cc0e52523560a8dfc12f5374e5d5ecf5375b Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Dec 2008 13:39:14 +0100 Subject: [S390] cio: commit all pmcw changes. Sometimes we change the pmcw configuration but don't call msch to transmit these changes to the channel subsystem. The patch fixes this by calling cio_commit_config in such cases. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_fsm.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/s390/cio/device_fsm.c') diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c index 9e249675c98d..8df5eaafc5ab 100644 --- a/drivers/s390/cio/device_fsm.c +++ b/drivers/s390/cio/device_fsm.c @@ -1031,6 +1031,8 @@ void ccw_device_trigger_reprobe(struct ccw_device *cdev) * paths are valid. */ io_subchannel_init_config(sch); + if (cio_commit_config(sch)) + return; /* We should also udate ssd info, but this has to wait. */ /* Check if this is another device which appeared on the same sch. */ -- cgit v1.2.3